/* 基础样式 - 所有页面共用 */

/* 重置样式 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --primary-color: #e41e26;
  --secondary-color: #1a1a1a;
  --white-color: #ffffff;
  --light-gray: #f4f4f4;
  --accent-color: #d4af37;
}

html, body {
  height: 100%;
  font-family: Arial, sans-serif;
  line-height: 1.6;
  color: var(--secondary-color);
  background-color: #fff;
}

body {
  padding-top: 80px;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  font-family: "Helvetica Neue", sans-serif;
  font-weight: bold;
  margin-bottom: 15px;
}

p {
  margin-bottom: 15px;
}

a {
  text-decoration: none;
  color: var(--secondary-color);
  transition: all 0.3s ease;
}

ul, ol {
  list-style: none;
}

img {
  max-width: 100%;
  height: auto;
}

/* 布局 */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 15px;
}

.row {
  display: flex;
  flex-wrap: wrap;
  margin-right: -15px;
  margin-left: -15px;
}

[class*="col-"] {
  padding-right: 15px;
  padding-left: 15px;
}

.col-md-6 {
  width: 100%;
}

@media (min-width: 768px) {
  .col-md-6 {
    width: 50%;
  }
}

/* 导航栏 */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background-color: #fff;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  z-index: 1000;
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 0;
}


.nav-menu {
  display: flex;
}

.nav-menu li {
  margin-left: 20px;
}

.nav-menu a {
  position: relative;
  padding: 5px 0;
}

.nav-menu a:after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  background: var(--primary-color);
  bottom: 0;
  left: 0;
  transition: width 0.3s;
}

.nav-menu a:hover:after,
.nav-menu a.active:after {
  width: 100%;
}

.mobile-nav-toggle {
  display: none;
  font-size: 24px;
  cursor: pointer;
}

/* 按钮 */
.btn {
  display: inline-block;
  padding: 10px 25px;
  background-color: var(--primary-color);
  color: var(--white-color);
  border: none;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.3s ease;
}

.btn:hover {
  background-color: #c41920;
  transform: translateY(-2px);
}

/* 页面标题 */
.page-title {
  background-color: var(--secondary-color);
  color: var(--white-color);
  padding: 60px 0 30px;
  text-align: center;
  margin-bottom: 40px;
}

/* 页脚 */
footer {
  background-color: var(--secondary-color);
  color: var(--white-color);
  padding: 60px 0 20px;
  margin-top: 60px;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 30px;
  margin-bottom: 40px;
}

.footer-column h3 {
  color: var(--accent-color);
  margin-bottom: 20px;
  font-size: 1.2rem;
}

.footer-column ul li {
  margin-bottom: 10px;
}

.footer-column ul li a {
  color: var(--white-color);
}

.footer-column ul li a:hover {
  color: var(--primary-color);
}

.footer-bottom {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

/* 返回顶部按钮 */
.back-to-top {
  position: fixed;
  right: 20px;
  bottom: 20px;
  width: 40px;
  height: 40px;
  background-color: var(--primary-color);
  color: var(--white-color);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  z-index: 999;
}

.back-to-top.active {
  opacity: 1;
  visibility: visible;
}

/* 响应式设计 */
@media (max-width: 991px) {
  .nav-menu {
    position: fixed;
    top: 80px;
    right: -100%;
    width: 250px;
    height: 100vh;
    background: var(--white-color);
    flex-direction: column;
    padding: 20px;
    box-shadow: -5px 0 10px rgba(0, 0, 0, 0.1);
    transition: right 0.3s ease;
  }
  
  .nav-menu.active {
    right: 0;
  }
  
  .nav-menu li {
    margin: 15px 0;
  }
  
  .mobile-nav-toggle {
    display: block;
  }
}

@media (max-width: 768px) {
  body {
    padding-top: 70px;
  }
  
  .page-title {
    padding: 40px 0 20px;
  }
  
  h1 {
    font-size: 1.8rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
}

/* 工具类 */
.text-center {
  text-align: center;
}

.mt-5 {
  margin-top: 3rem;
}

.mb-4 {
  margin-bottom: 2rem;
}

.d-flex {
  display: flex;
}

.justify-content-center {
  justify-content: center;
}

.align-items-center {
  align-items: center;
}